Inorganic: Inorganic means that the mineral is not from materials that were once a living thing. Crystal: Particles of a mineral that are in a repeating pattern and forms a solid is called a crystal. Element: A substance that is composed of a single kind of atom. Compound: A substance that is composed of two or more elements and are combined so that the elements no longer have distinct properties. Mohs Hardness Scale: A scale that ranks ten minerals from softest to hardest. Streak: The color of a minerals powder is called the streak. Luster: The term used to describe the amount of light the mineral reflects. Cleavage: The property of some minerals that break easily on flat surfaces. Fracture: A description of how a mineral looks when it breaks apart in an irregular way. Fluorescence: A property of some minerals that glow under ultraviolet light.
Outline
Introduction
If you have ever been to a museum, you might have seen a place called the " Hall of Minerals".
Over there, many minerals are displayed that you have never heard or seen.
One good example is " sphalerite. "
Sphalerite is a mineral that has a ruby red color.
It is also a source of zinc and gallium and these metals are used in products from" tin cans " to computer chips.
What Is a Mineral
A mineral is an inorganic solid that naturally occurs which has a definite chemical composition.
Naturally Occurring
Cement, bricks, steel and glass are not naturally occurring as they are made from substances found in the crust and then manufactured.
Inorganic
A mineral that is inorganic means that it is not from materials that were once parts of living things.
One example of an inorganic mineral is coal.
It is made from dead plants and animals.
Solid
Minerals are always solids as their particles are packed very tightly together so that they won't move like the particles in a liquid.
It is always has a definite volume and shape.
Crystal Structure
Crystals are particles of a mineral that are in a repeating pattern and form solids called crystals.
A crystal has flat sides ( which are technically called faces ) that meet at sharp edges called corners.
Definite Chemical Composition
A mineral always has a definite chemical composition as it always contains a certain amount of elements.
An element is a substance that is composed of a single kind of atom.
All the atoms of an element carry the same physical and chemical properties.
Almost all of the minerals that scientists have discovered are compounds.
A compound is a substance that is composed of two or more elements which are combined so that the elements no longer have distinct properties.
The elements of a compound are said to be chemically joined.
Each compound has its own properties that are usually different from the properties of elements that form it.
An example of a compound is cinnabar.
It is made from the elements mercury and sulfur.
Identifying Minerals
Every mineral has its own specific properties which could be used to identify it.
Minerals are identified by hardness, color, streak, luster, density, crystal systems, cleavage and fractures and their special properties.
Hardness
To identify the minerals hardness, a scientist named Friedrich Mohs, who was Australian, invented the Mohs Hardness Scale.
The Mohs Hardness Scale is a scale that ranks ten minerals from softest to hardest.
The softest known mineral is talc and the hardest is diamond.
Color
The color of a mineral can be an easily observed physical property.
Some minerals have their own characteristic color.
One example of a mineral that always has the same color is malachite.
Its color is always green.
Another example is azurite.
Its color is always blue.
There are also many minerals that have a range of colors.
A good example would be quartz as it comes in all sorts of colors.
Streak
The streak of a mineral is basically the color of its powder.
You can observe streaks when you rub a mineral on an unglazed plate which is also called a streak plate.
Luster
A luster of a mineral is the term used to describe the amount of light the mineral reflects.
Minerals that contain metals have a shiny luster.
Other terms are bright, metallic, earthy, silky, waxy, and pearly.
Density
Each mineral has its own special density
When geologists measure density, they use a balance to determine the mass of the sample
Geologists also put the minerals in water to see how much water the mineral displaces.
The amount of displaced water is the volume of the mineral and dividing the volume of the mineral by its mass gives you the density of the mineral.
Crystal Systems
Each mineral has its own crystal system
For example, magnetite and halite have a cubic crystal system while sulfur has a orthorhombic crystal system
Cleavage and Fracture
Cleavage
A mineral which can split easily along flat surfaces has the property known as cleavage
Depending on the arrangement of atoms in a mineral, it will break easier in one direction than in another
Feldspar and mica are two minerals which have cleavage
Fracture
The way a mineral looks after an irregular break is its fracture
Fractured quartz has a shell-shaped fracture, pure metals such as copper and iron, have a hackly fracture and soft minerals like clay have an earthy fracture.
Special Properties
Some minerals have the property known as fluorescence which is the ability to grow under an ultra-violet light.
Table of Contents
4.1 Properties of Minerals
Vocabulary
Inorganic: Inorganic means that the mineral is not from materials that were once a living thing.
Crystal: Particles of a mineral that are in a repeating pattern and forms a solid is called a crystal.
Element: A substance that is composed of a single kind of atom.
Compound: A substance that is composed of two or more elements and are combined so that the elements no longer have distinct properties.
Mohs Hardness Scale: A scale that ranks ten minerals from softest to hardest.
Streak: The color of a minerals powder is called the streak.
Luster: The term used to describe the amount of light the mineral reflects.
Cleavage: The property of some minerals that break easily on flat surfaces.
Fracture: A description of how a mineral looks when it breaks apart in an irregular way.
Fluorescence: A property of some minerals that glow under ultraviolet light.
Outline
Introduction
What Is a Mineral
Identifying Minerals
- Color
- The color of a mineral can be an easily observed physical property.
- Some minerals have their own characteristic color.
- One example of a mineral that always has the same color is malachite.
- Its color is always green.
- Another example is azurite.
- Its color is always blue.
- There are also many minerals that have a range of colors.
- A good example would be quartz as it comes in all sorts of colors.
- Streak
- The streak of a mineral is basically the color of its powder.
- You can observe streaks when you rub a mineral on an unglazed plate which is also called a streak plate.
- Luster
- A luster of a mineral is the term used to describe the amount of light the mineral reflects.
- Minerals that contain metals have a shiny luster.
- Other terms are bright, metallic, earthy, silky, waxy, and pearly.
- Density
- Each mineral has its own special density
- When geologists measure density, they use a balance to determine the mass of the sample
- Geologists also put the minerals in water to see how much water the mineral displaces.
- The amount of displaced water is the volume of the mineral and dividing the volume of the mineral by its mass gives you the density of the mineral.
- Crystal Systems
- Each mineral has its own crystal system
- For example, magnetite and halite have a cubic crystal system while sulfur has a orthorhombic crystal system
- Cleavage and Fracture
- Cleavage
- A mineral which can split easily along flat surfaces has the property known as cleavage
- Depending on the arrangement of atoms in a mineral, it will break easier in one direction than in another
- Feldspar and mica are two minerals which have cleavage
- Fracture
- The way a mineral looks after an irregular break is its fracture
- Fractured quartz has a shell-shaped fracture, pure metals such as copper and iron, have a hackly fracture and soft minerals like clay have an earthy fracture.
- Special Properties
- Some minerals have the property known as fluorescence which is the ability to grow under an ultra-violet light.
- These are some examples.
- Lodestone ( natural magnet )
- Uraninite ( radioactive )
- Quartz ( electric properties )
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